jq 从 json 中选择动态项

Question

我有这样的 JSON：

{
  "photo_807": "Ih2RnaBTg2o.jpg",
  "photo_604": "zodCm9fQgX8.jpg",
  "photo_130": "4Dx-SUNKBw4.jpg",
  "photo_75": "7COWb8ou1qA.jpg",
  "user_id": 100,
  "owner_id": -2435432542783750,
  "access_key": "fc5275423676514042234324265cc3df7607c",
  "post_id": 380435645368865101,
  "date": 14858616848616779856424245814,
  "text": "",
  "height": 417,
  "width": 740,
  "id": 45624575446886886564368555,
  "album_id": -36
}

我只想获取照片值，从输出中我想得到这个：

"photo_807": "Ih2RnaBTg2o.jpg"
"photo_604": "zodCm9fQgX8.jpg"
"photo_130": "4Dx-SUNKBw4.jpg"

现在关于我的问题，从下一个 JSON 文件中，我将获得具有新名称的照片项目，如下所示：

  "photo_181": "Ih2RnaBTg2o.jpg",
  "photo_583": "zodCm9fQgX8.jpg",
  "photo_975": "4Dx-SUNKBw4.jpg",
  "photo_32": "7COWb8ou1qA.jpg",

如何从动态项目 photo_* 中获取该值？

我尝试这样的事情：

  cat  ./json3.txt | jq  '.response.items[].attachments[].photo | select(.photo | startswith("photo"))'

但这不起作用。

当我跑步时：

cat  ./json3.txt | jq  '.response.items[].attachments[].photo'  

我得到了所有项目的输出：

{
  "photo_807": "Ih2RnaBTg2o.jpg",
  "photo_604": "zodCm9fQgX8.jpg",
  "photo_130": "4Dx-SUNKBw4.jpg",
  "photo_75": "7COWb8ou1qA.jpg",
  "user_id": 100,
  "owner_id": -2435432542783750,
  "access_key": "fc5275423676514042234324265cc3df7607c",
  "post_id": 380435645368865101,
  "date": 14858616848616779856424245814,
  "text": "",
  "height": 417,
  "width": 740,
  "id": 45624575446886886564368555,
  "album_id": -36
}

有人能帮我吗？

提前致谢！

Answer 1

您可以使用jq如下过滤器，如在jq-play上测试的那样！

jq '. | to_entries[] | select(.key | startswith("photo")) | "\(.key) :\(.value)"' json
"photo_807 :Ih2RnaBTg2o.jpg"
"photo_604 :zodCm9fQgX8.jpg"
"photo_130 :4Dx-SUNKBw4.jpg"
"photo_75 :7COWb8ou1qA.jpg"

这个想法是使用内置的to_entries[]，它将您的输入转换为键值对，如下所示。请参阅下面仅使用的输出to_entries[]

jq '. | to_entries[]' json
{
  "key": "photo_807",
  "value": "Ih2RnaBTg2o.jpg"
}
{
  "key": "photo_604",
  "value": "zodCm9fQgX8.jpg"
}
{
  "key": "photo_130",
  "value": "4Dx-SUNKBw4.jpg"
}
{
  "key": "photo_75",
  "value": "7COWb8ou1qA.jpg"
}
{
  "key": "user_id",
  "value": 100
}
{
  "key": "owner_id",
  "value": -2435432542783750
}
{
  "key": "access_key",
  "value": "fc5275423676514042234324265cc3df7607c"
}
{
  "key": "post_id",
  "value": 380435645368865100
}
{
  "key": "date",
  "value": 14858616848616779000000000000
}
{
  "key": "text",
  "value": ""
}
{
  "key": "height",
  "value": 417
}
{
  "key": "width",
  "value": 740
}
{
  "key": "id",
  "value": 45624575446886885000000000
}
{
  "key": "album_id",
  "value": -36
}

在此输出中，我们正在过滤以.key您的字符串开头的值（photo在您的情况下），使用内置的startswith()，并打印匹配对象的.key和对。.value